Tragic Rug,
I’m sure you have realised by now that the “Prof” part of my nickname stands for Professor rather than Professional, and hence my questions. At the MSc level, and with the dissertation being worth 1/3 of the overall marks given for the course, the implication is that you are able to spend some time and effort on the dissertation.
The payload/range graph you should be able to build yourself, and it is probably an integral part of your dissertation anyway. If you are comparing aircraft economics, then you’ll need to have constructed your own spreadsheet model of weights, loads, fuel burn, etc so as to do your dissertation. For the An124, Janes will give you the starting data.
There are a couple of techniques I can share with you. The first is to create a model for another aircraft on which the data is freely available. For no reason other than I spent this weekend frantically rebuilding the models for the 737-800 economics for my work, can I suggest you build the model for that aircraft. I am happy to help you as you do that, and I suggest we do it publicly through Tech Log as part of a contribution to knowledge. Starting points are weights and fuel burn. Ending point is, well say, the takeoff weight to haul 140 pax and 300 dozen beers from Perth to Broome in bad weather.
Once you have built the model for an aircraft that can be verified, you will find that modelling the An124 (and the BC17) will be child’s play.
The second technique is what I (and fellow kubuer EH) have used very successfully in our professional work. And that is to start at the end and work back. For the runway length graph, if you don’t have one, than use one from another similar aircraft and do your work based on that. You will eventually get something for the An124 and then need only adjust figures slightly in your models. So think through what aircraft is not-too dissimilar and for which data is available, then tell us what you’ll choose.